For example, a common mode choke coil described in Japanese Patent No. 4209851 is known as a disclosure related to a common mode filter in related art. FIG. 30 is a cross-sectional view illustrating an exemplary structure of a common mode choke coil 510 described in Japanese Patent No. 4209851. The vertical direction in FIG. 30 is hereinafter simply referred to as a vertical direction.
The common mode choke coil 510 includes a multilayer body 512 and coils 514, 516, and 518. The coils 514, 516, and 518 each form a spiral shape in which the coil winds clockwise from an outer periphery side to an inner periphery side, viewed from the upper side. The coils 514, 516, and 518 are overlapped with each other. The coil 518 is vertically sandwiched between the coil 514 and the coil 516. In the common mode choke coil 510 described above, a high-frequency signal is transmitted to the coils 514 and 516 and ground potential is connected to the coil 518.